WASHINGTON (CNN) -- The U.S. military hopes to kill or capture some 50 Afghan drug traffickers with financial ties to the Taliban in an effort to shut down one of the insurgency's biggest sources of revenue, a U.S. Senate report says.

Afghan men smoke heroin in the city of Herat on August 7, 2009.

The new plan is the first time the U.S. military has been directly involved in anti-narcotics efforts in Afghanistan, and commanders say it is an essential part of the overall plan to stabilize the country, which is under heavy Taliban influence.

Until now the U.S. military has left the eradication programs to other U.S. agencies and the Afghan military, keeping its "most wanted" list to insurgent leaders tied to bomb making, weapons smuggling or facilitating foreign fighters into the country.

"The change is dramatic for a military that once ignored the drug trade flourishing in front of its eyes," according to the report. "No longer are U.S. commanders arguing that going after the drug lords is not part of their mandate."

It does not name the 50 targets, but says they are on a list of 367 names of Taliban and other insurgents targeted by the U.S. military.

"Some" of the 50 have already been apprehended or killed, according to a senior military official. The official would not quantify the amount further and would not speak on the record because of the sensitive nature of the issue.

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The yet-to-be released report was prepared by staff for members of the Senate Foreign Relations Committee. A copy was provided to CNN. It is based on testimony by U.S. military officials to the committee.

Bush-era efforts by the United States and the U.S.-trained Afghan Army to eliminate poppy farms did very little to solve the problem, with numerous farmers' crops flourishing while other farmers were left with no source of income and bitterness toward the Afghan government, the report concludes.

It criticizes former Secretary of Defense Donald Rumsfeld for failing to push forward on a military role in drug eradication even after being shown proof of the connection between the drug lords and the Taliban.

The change in the U.S. military's approach to fighting the drug war came last fall after the United States told NATO members that the drug trade was a threat to NATO troops because there was a direct connection between it and Taliban insurgents in Afghanistan.

"There is what we call a nexus of insurgency. There's a very broad range of militant groups that are combined with the criminality, with the narco-trafficking system, with corruption, that form a threat and a challenge to the future of that great country," then-U.S. commander in Afghanistan Gen. David McKiernan told reporters at the Pentagon last October.

But with a new approach to the war by the Obama administration, the United States has started attacking the drug problem head on.

According to the report, this year U.S. and NATO combat forces started attacking militants, drug labs and buildings connected to insurgents with ties to drug lords for the first time since the start of the war in 2001.

Referring to people tied to narcotics and militants, the report says, "The military places no restrictions on the use of force with these selected targets, which means they can be killed or captured on the battlefield."

The Pentagon's spokesman said the effort is still focused on fighting terrorism.

"There is a well-established link [between] the drug trade and financing of the insurgency and terrorism," said spokesman Bryan Whitman. "It's important to delineate that we target terrorists that are connected to the drug trade. ... Terrorist do interface with drug networks and we know they provide finance for the insurgency, and it's this nexus that creates the security and force-protection issues that make them a legitimate target."

A major U.S. Marine offensive against the Taliban was launched last month in the southern Afghan province of Helmand, home to the majority of the poppy farms and opium trade. The report says the Taliban make about $70 million a year on the drug trade.

The report concedes that counter-narcotics alone will not win the war, but says slowing the flow of illicit money will play a crucial role in "determining whether we can carve out the space required to provide the security and economic development necessary to bring a level of stability to Afghanistan."